Consumers in 37 states that want affordable marketplace health coverage are more likely to pick a plan from Coventry, Humana or WellPoint, according to new research by Avalere Health.

Coventry had the largest share of its health plans priced competitively, with more than half priced equal to or less than the area "benchmark" plan, which is the second lowest-cost silver plan.

Sixty-five percent of the nation's 8 million marketplace enrollees selected a silver plan, which covers 70 percent of medical costs. Ninety-five percent of silver plan members who enrolled through the federal marketplace, HealthCare.gov, qualified for financial assistance to help pay for coverage.

Humana, Coventry, and the new consumer operated and oriented plans, known as "co-ops," had the largest share of affordable silver plans. While over 60 percent of Humana's silver plans were priced the same or less than area benchmark plans, according to the research which looked at plans in California, Idaho, New Mexico and the 34 states that use the federal health insurance marketplace.

Overall, independent Blue Cross Blue Shield plans, known as "Blues," had the most low-cost silver plans with 370 in 27 states.

“Securing enrollment in silver plans is critical for carriers establishing exchange market share,” said Elizabeth Carpenter, director at Avalere Health. “Looking ahead to 2015, we expect silver plans to remain the most popular given the link between the silver level and federal financial assistance, including tax credits and cost-sharing reductions.”